The Behavioural Assessment Scale of Later Life (BASOLL): A Description, Factor Analysis, Scale Development, Validity and Reliability Data for a New Scale for Older Adults.

Preliminary data on the Behavioural Assessment Scale of Later Life (BASOLL) (Brooker and Nissenbaum, 1986) are described. The BASOLL is based upon Zarit's Memory and Behavioural Problem Checklist (MBPC; Zarit et al., 1980) and the Blessed Dementia Scale (BDS; Blessed et al., 1968). The BASOLL was administered to a sample of 177 psychogeriatric patients over a period of 2 years during regular clinical practice in outpatient, day patient and inpatient settings. A factor analysis revealed three factors which were named self-care behaviour, memory and orientation, and challenging behaviour. The similarity with factors derived from Zarit's MBPC is discussed. Summative scales derived from the factor analysis of the BASOLL were internally consistent. Data on test-retest and interrater reliability are presented which suggest that the scales are reliable. The scales included in the BASOLL were all able to distinguish between patients in day hospital, respite care and continuing care settings. Thus the scales can be said to have good criterion validity for these settings. The clinical development and utility of the BASOLL is discussed.